Is PTSD-Phenotype Associated with HPA-Axis Sensitivity? Feedback Inhibition and Other Modulating Factors of Glucocorticoid Signaling Dynamics

Previously, we found that basal corticosterone pulsatility significantly impacts the vulnerability for developing post-traumatic stress disorder (PTSD). Rats that exhibited PTSD-phenotype were characterized by blunted basal corticosterone pulsatility amplitude and a blunted corticosterone response to a stressor. This study sought to identify the mechanisms underlining both the loss of pulsatility and differences in downstream responses. Serial blood samples were collected manually via jugular vein cannula at 10-min intervals to evaluate suppression of corticosterone following methylprednisolone administration. The rats were exposed to predator scent stress (PSS) after 24 h, and behavioral responses were assessed 7 days post-exposure for retrospective classification into behavioral response groups. Brains were harvested for measurements of the glucocorticoid receptor, mineralocorticoid receptor, FK506-binding protein-51 and arginine vasopressin in specific brain regions to assess changes in hypothalamus–pituitary–adrenal axis (HPA) regulating factors. Methylprednisolone produced greater suppression of corticosterone in the PTSD-phenotype group. During the suppression, the PTSD-phenotype rats showed a significantly more pronounced pulsatile activity. In addition, the PTSD-phenotype group showed distinct changes in the ventral and dorsal CA1, dentate gyrus as well as in the paraventricular nucleus and supra-optic nucleus. These results demonstrate a pre-trauma vulnerability state that is characterized by an over-reactivity of the HPA and changes in its regulating factors.

Combining Magnetic Resonance Imaging with Systemic Monocyte Evaluation for the Implementation of GBM Management

Magnetic resonance imaging (MRI) is the gold standard for glioblastoma (GBM) patient evaluation. Additional non-invasive diagnostic modalities are needed. GBM is heavily infiltrated with tumor-associated macrophages (TAMs) that can be found in peripheral blood. FKBP51s supports alternative-macrophage polarization. Herein, we assessed FKBP51s expression in circulating monocytes from 14 GBM patients. The M2 monocyte phenotype was investigated by qPCR and flow cytometry using antibodies against PD-L1, CD163, FKBP51s, and CD14. MRI assessed morphologic features of the tumors that were aligned to flow cytometry data. PD-L1 expression on circulating monocytes correlated with MRI tumor necrosis score. A wider expansion in circulating CD163/monocytes was measured. These monocytes resulted in a dramatic decrease in patients with an MRI diagnosis of complete but not partial surgical removal of the tumor. Importantly, in patients with residual tumor, most of the peripheral monocytes that in the preoperative stage were CD163/FKBP51s- had turned into CD163/FKBP51s+. After Stupp therapy, CD163/FKBP51s+ monocytes were almost absent in a case of pseudoprogression, while two patients with stable or true disease progression showed sustained levels in such circulating monocytes. Our work provides preliminary but meaningful and novel results that deserve to be confirmed in a larger patient cohort, in support of potential usefulness in GBM monitoring of CD163/FKBP51s/CD14 immunophenotype in adjunct to MRI.

Proteomic analysis of infected primary human leucocytes revealed PSTK as potential treatment-monitoring marker for active and latent tuberculosis

Markers for monitoring clearance of Mycobacterium tuberculosis (Mtb) infection during anti-TB drug treatment could facilitate management of tuberculosis (TB) treatment, but are lacking. We aimed to screen for Mtb clearance markers from in-vitro-infected leucocytes and to evaluate these markers in followed-up active TB (ATB) patients and latent TB (LTBI) cases after anti-TB drug treatment. Extracellular proteins from primary leucocytes infected with each of the Mtb lineages (East-Asian, Indo-Oceanic, Euro-American and the laboratory strain H37Rv) were screened as possible clearance markers. Leucocytes infected with Staphylococcus aureus acted as controls. The proteomic analysis was performed using GeLC-MS/MS. Several quantitative and qualitative candidate clearance markers were found. These proteins were suppressed during the infection stage of all Mtb lineages and re-expressed after bacillary clearance. PSTK, FKBP8 and MGMT were common clearance markers among the four Mtb lineages in our model. Only PSTK was a potential clearance marker based on western blot validation analysis from culture supernatants. The PSTK marker was further validated with western blot analysis using serum samples (n = 6) from ATB patients and LTBI cases during anti-TB drug treatment, and from healthy controls (n = 3). Time-dependent increase of PSTK was found both in ATB and LTBI patients during the course of anti-TB drug treatment, but not in healthy controls. We have demonstrated that PSTK is a potential treatment-monitoring marker for active and latent TB.

FKBP5 mRNA Expression Is a Biomarker for GR Antagonism

CONTEXT

Endogenous Cushing's syndrome is caused by chronically elevated levels of cortisol. Mifepristone, a glucocorticoid receptor (GR) antagonist, is approved for the treatment of Cushing's syndrome. Currently there is an unmet clinical need for a direct biochemical method for monitoring the immediate effectiveness of mifepristone in patients with Cushing's syndrome. The glucocorticoid induction of FK506-binding protein 5 (FKBP5) expression is rapid and has been shown to be attenuated by GR antagonists in a range of in vitro and in vivo models.

OBJECTIVE

The objective of the study was to develop a quantitative PCR assay for FKBP5 mRNA expression in blood and apply it to measure the inhibition of glucocorticoid-induced FKBP5 expression by GR antagonists in healthy human subjects.

METHODS

Briefly, blood samples were acquired from a phase I study in which healthy human subjects were administered either a single dose of the GR agonist prednisone with and without coadministration of a single oral dose of mifepristone or glucocorticoid receptor antagonist (CORT125134) or multiple daily doses of CORT125134 over 14 days with coadministration of prednisone with the final dose. FKBP5 mRNA levels were analyzed by quantitative PCR in blood samples collected at selected time points.

SETTING

The study was conducted at Quotient Clinical (Nottingham, United Kingdom).

RESULTS

Oral administration of the glucocorticoid prednisone to healthy human subjects resulted in a time-dependent increase of FKBP5 mRNA to peak levels of approximately 12-fold compared with unstimulated levels within 4 hours of steroid administration, followed by a reduction to baseline levels within 24 hours. Furthermore, oral administration of mifepristone or the selective GR antagonist CORT125134 had the desired effect of inhibiting prednisone-mediated activation of GR as seen by a reduction of FKBP5 mRNA levels.

CONCLUSIONS

The inhibition of FKBP5 mRNA expression by a selective GR antagonist is a potential clinical biomarker of GR antagonism.

Doping control analysis of emerging drugs in human plasma - identification of GW501516, S-107, JTV-519, and S-40503

An important aspect of preventive doping research is the rapid implementation of tests for emerging drugs with potential for misuse into routine doping control assays. New therapeutics of different classes such as PPARdelta-agonists (e.g. GW501516), ryanodine-calstabin-complex stabilizers (e.g. S-107 and JTV-519), and selective androgen receptor modulators (SARMs, e.g. S-40503) are currently used for the treatment of particular medical conditions such as metabolic syndrome, cardiac arrhythmia, debilitating diseases and osteoporosis, respectively. Due to their being at an early stage of clinical trials and the limited availability of data on the metabolism and possible renal elimination of the active drugs, the development of protocols for doping control analyses of plasma specimens could be an option for the detection of the circulating agents. The mass spectrometric fragmentation of four emerging drug candidates (GW501516, S-107, JTV-519, and S-40503) was elucidated by positive electrospray ionization and collision-induced dissociation using a high resolution/high accuracy mass spectrometer. A screening and confirmation procedure was established based on liquid chromatography/tandem mass spectrometry requiring a volume of 100 microL of plasma. Proteins were precipitated using acetonitrile, the specimens were centrifuged and the supernatant analyzed using a triple-quadrupole mass spectrometer employing multiple reaction monitoring of diagnostic ion transitions. The method was validated with regard to specificity, limits of detection (0.4-8.3 ng/mL), recoveries (72-98%), intraday and interday precisions (12-21%), and ion suppression/enhancement effects.

Monitoring protein expression by proteomics: human plasma exposed to benzene

Low levels and long term exposure to benzene is associated with hematotoxicity including aplastic anemia, acute myelogenous leukemia, and lymphoma. Current biomonitoring methods such as urinary phenol, S-phenylmercapturic acid, and trans-trans muconic acid were found to be unreliable as analytical methods to detect benzene exposure. Therefore, to search for a specific protein for biomonitoring benzene exposure, we investigated plasma proteins from workers (n = 50) at a printing company who were exposed to benzene, by two-dimensional gel electrophoresis. The protein profiles are significantly different (p < 0.05) between benzene exposed and unexposed groups, as identified by matrix-assisted laser desorption ionization/time of flight mass spectrometry and confirmed by Western blot analyses. T cell receptor beta chain (TCR beta), FK506-binding protein, and matrix metalloproteinase-13 were expressed only in benzene exposed workers. In addition, interleukin-4 receptor alpha chain and T cell surface glycoprotein CD1b precursor were found to be up-regulated in the plasma of benzene exposed workers. When we treated Jurkat cells with benzene (10 microM-10 mM), TCR beta expression was increased in the membrane more than 6-9-fold compared to untreated cells. In addition, the amount of TCR beta released into the culture media, at benzene concentrations greater than 50 microM, increased up to 10 mM. Therefore, TCR beta levels in plasma could be used as a biomarker and a possible therapeutic target for benzene exposure.